C-reactive protein predicts response to infliximab in patients with chronic sarcoidosis

This study assessed the value of C-reactive protein as a predictor of disease severity and response to infliximab therapy in patients with chronic pulmonary sarcoidosis. Sera were collected through week 52 from 138 patients with chronic pulmonary sarcoidosis who received placebo or infliximab in a randomized, double-blind, placebo-controlled study. We evaluated the response to therapy by baseline CRP using a dichotomous cutpoint (0.8 mg/dL) for the change from baseline in percent-predicted forced vital capacity (FVC), Saint George's Respiratory Questionnaire (SGRQ), 6-minute walk distance (6MWD), Borg's CR10 dyspnea score, and Physician Organ Assessment (POA). CRP was elevated in 36% of patients at baseline, and was significantly reduced by infliximab by week 2. Among patients with elevated baseline CRP, infliximab-treated patients improved significantly compared with placebo-treated patients in percent-predicted FVC (+2.5 versus -2.6%), 6MWD (+8.0 versus -34.1), Borg's CR10 dyspnea score (pre-6MWD -0.8 versus +0.9, post-6MWD -1.1 versus +0.8), and POA (-3.1 versus -0.3). Patients with lower CRP levels at baseline did not show significant differences between the placebo and infliximab groups in most endpoints evaluated. In chronic sarcoidosis patients, elevated CRP appears to identify a subset with more severe disease who may respond better to treatment with infliximab.